International Stroke Conference (ISC)
February 17-19, 2016
February 17, 2016
At the International Stroke Conference, a panel of experts discussed various clinical questions in regards to patient selection for endovascular intervention that were not addressed in recent trials. This questions include stroke severity, age, need for imaging, time, and location.
Dr. Khatri discussed stroke severity. Mild strokes were excluded from the recent endovascular trials thus leading to the ASA recommendation of endovascular intervention for strokes with NIHSS > 6. Within the trials, only 14 patients were treated with NIHSS 0-5 so treatment affect and benefit within this subset population is relatively unknown. It’s possible that such patients are mislabeled as “mild” stroke and inappropriately excluded from acute revascularization therapy. The focus should be less on absolute NIHSS number but rather on actual disability. An ACA infarct can register a low NIHSS but can be extremely disabling and should be offered revascularization therapy.
Dr. Powers discussed the important risk factor of age and whether there should be an upper limit. The data suggests limited benefit beyond age > 80 but there are no controls. What is clear from the data that untreated patients do worse and the focus should be on relative benefit rather than absolute benefit. A consensus is age alone should not be a contraindication and treatment decisions should factor baseline health and functional status. There are sufficient anecdotal evidence of successful endovascular treatment with good clinical outcome in octogenarians with a normal functional status at baseline.
Dr. Yoo discussed perhaps one of the more controversial topics of how much imaging is actually required before proceeding with intervention. Many hospitals have adopted CT and CTA scan as their “default” imaging in order to determine eligibility and this has also been adopted within guidelines as well. The dilemma becomes when there are CT hypodensities and more data is needed for ASPECTS of 0-4. In this scenario, it is reasonable to proceed with perfusion imaging to assess for penumbra. DEFUSE-2 is on-going study addressed to determine if perfusion imaging can identify patients for clot retrieval.
Dr. Jovin addressed the important factor of time and when is it getting too late for intervention. It has been well established that collaterals determine rate of infarct growth. Furthermore, patients with good collaterals have also been shown to do well without intervention as well. Therefore, selecting patients based solely on collaterals may be a self-fulfilling prophecy. Two trials are currently underway evaluating outcomes in patients with delayed presentation.
Lastly, Dr. Noguiera discussed the influence of site of occlusion on treatment. Vast majority of patients treated in the trials were large proximal artery occlusion (ICA, M1). With improving technology, clot retrieval is achievable for other sites including ACA, PCA, and M3. However, data on such infarcts are sparse. Only 3 ACA occlusions were included within MR CLEAN. The decision to intervene upon smaller vessels should be based upon risk and benefit. There is greater risk to intervene upon smaller vessels, especially as tortuousity increases, and decision should be based upon other factors including stroke syndrome and anatomy.
– Jay Shah, MD